[PATCH V3 21/26] coresight: introducing a global trace ID function
From: mathieu.poirier@linaro.org (Mathieu Poirier)
Date: 2015-11-11 22:21:45
Also in:
lkml
Subsystem:
arm/coresight framework and drivers, hardware tracing facilities, the rest · Maintainers:
Suzuki K Poulose, Alexander Shishkin, Linus Torvalds
TraceID values have to be unique for all tracers and consistent between drivers and user space. As such introducing a central function to be used whenever a traceID value is required. The patch also account for data traceIDs, which are usually I(N) + 1. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- drivers/hwtracing/coresight/coresight-etm3x.c | 7 ++----- include/linux/coresight-pmu.h | 12 ++++++++++++ 2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index c07b7d3eee86..ebd569986bd4 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c@@ -27,6 +27,7 @@ #include <linux/cpu.h> #include <linux/of.h> #include <linux/coresight.h> +#include <linux/coresight-pmu.h> #include <linux/amba/bus.h> #include <linux/seq_file.h> #include <linux/uaccess.h>
@@ -784,11 +785,7 @@ static void etm_init_arch_data(void *info) static void etm_init_trace_id(struct etm_drvdata *drvdata) { - /* - * A trace ID of value 0 is invalid, so let's start at some - * random value that fits in 7 bits and go from there. - */ - drvdata->traceid = 0x10 + drvdata->cpu; + drvdata->traceid = coresight_get_trace_id(drvdata->cpu); } static int etm_probe(struct amba_device *adev, const struct amba_id *id)
diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h
index 6c5386b23b10..7d410260661b 100644
--- a/include/linux/coresight-pmu.h
+++ b/include/linux/coresight-pmu.h@@ -19,9 +19,21 @@ #define _LINUX_CORESIGHT_PMU_H #define CORESIGHT_ETM_PMU_NAME "cs_etm" +#define CORESIGHT_ETM_PMU_SEED 0x10 /* ETMv3.5/PTM's ETMCR config bit */ #define ETM_OPT_CYCACC 12 #define ETM_OPT_TS 28 +static inline int coresight_get_trace_id(int cpu) +{ + /* + * A trace ID of value 0 is invalid, so let's start at some + * random value that fits in 7 bits and go from there. Since + * the common convention is to have data trace IDs be I(N) + 1, + * set instruction trace IDs as a function of the CPU number. + */ + return (CORESIGHT_ETM_PMU_SEED + (cpu * 2)); +} + #endif
--
1.9.1